[Scummvm-git-logs] scummvm master -> 47c0e2701796962edd946ae463ae92ba806c4280

sev- sev at scummvm.org
Sat Aug 18 16:31:03 CEST 2018 

This automated email contains information about 5 new commits which have been
pushed to the 'scummvm' repo located at https://github.com/scummvm/scummvm .

Summary:
9cfc70e7fe COMMON: allow cos/sin number of points to be more flexible
e859a6f13e BLADERUNNER: Update cos/sin table constructor change
da57cef0c3 COMMON: FFT update cos/sin table constructor change
0805ac2be3 STARTREK: Update cos/sin table constructor change
47c0e27017 STARTREK: Simplify sine table usage


Commit: 9cfc70e7fe881cfbd680322b6beeb9a7ab7149c3
    https://github.com/scummvm/scummvm/commit/9cfc70e7fe881cfbd680322b6beeb9a7ab7149c3
Author: David Fioramonti (dafioram at gmail.com)
Date: 2018-08-18T16:30:57+02:00

Commit Message:
COMMON: allow cos/sin number of points to be more flexible

Previously, the cos/sin table had to be a power of 2, but there
are many use cases where the number of points is not necessarily
a power of 2 so this change the constructor so it now takes
in the number of points rather than the number of points as the
exponent of a power of 2.

The restriction is that the size must be divisible by 4.

Changed paths:
    common/cosinetables.cpp
    common/cosinetables.h
    common/sinetables.cpp
    common/sinetables.h


diff --git a/common/cosinetables.cpp b/common/cosinetables.cpp
index 42c6e4e..589c7c7 100644
--- a/common/cosinetables.cpp
+++ b/common/cosinetables.cpp
@@ -27,12 +27,11 @@
 
 namespace Common {
 
-CosineTable::CosineTable(int bitPrecision) {
-	assert((bitPrecision >= 4) && (bitPrecision <= 16));
+CosineTable::CosineTable(int nPoints) {
+	assert((nPoints >= 16) && (nPoints <= 65536)); // log2 space is in [4,16]
+	assert(nPoints % 4 == 0);
 
-	_bitPrecision = bitPrecision;
-
-	_nPoints = 1 << _bitPrecision;
+	_nPoints = nPoints;
 	_radResolution = 2.0 * M_PI / _nPoints;
 	_refSize = _nPoints / 4;
 	_table = new float[_nPoints / 2];
diff --git a/common/cosinetables.h b/common/cosinetables.h
index c08bb4c..ac0aef8 100644
--- a/common/cosinetables.h
+++ b/common/cosinetables.h
@@ -28,40 +28,34 @@ namespace Common {
 class CosineTable {
 public:
 	/**
-	 * Construct a cosine table with the specified bit precision
+	 * Construct a cosine table given the number of points
 	 *
-	 * @param bitPrecision Precision of the table, which must be in range [4, 16]
+	 * @param nPoints Number of distinct radian points, which must be in range [16,65536] and be divisible by 4
 	 */
-	CosineTable(int bitPrecision);
+	CosineTable(int nPoints);
 	~CosineTable();
 
 	/**
 	 * Get pointer to table.
 	 *
-	 * This table contains 2^bitPrecision/2 entries.
+	 * This table contains nPoints/2 entries.
 	 * Prefer to use at()
 	 * The layout of this table is as follows:
-	 * - Entries 0 up to (including) 2^bitPrecision/4:
+	 * - Entries 0 up to (including) nPoints/4:
 	 *           cos(0) till (including) cos(1/2*pi)
-	 * - Entries (excluding) 2^bitPrecision/4 up to 2^bitPrecision/2:
+	 * - Entries (excluding) nPoints/4 up to nPoints/2:
 	 *           (excluding) cos(3/2*pi) till (excluding) cos(2*pi)
 	 */
 	const float *getTable() { return _table; }
 
 	/**
-	 * Returns cos(2*pi * index / 2^bitPrecision )
-	 * Index must be in range [0,2^bitPrecision-1]
+	 * Returns cos(2*pi * index / nPoints )
+	 * Index must be in range [0, nPoints - 1]
 	 */
 	float at(int index) const;
 
-	/**
-	 * Get bit precision
-	 */
-	int getBitPrecision() { return _bitPrecision; }
-
 private:
 	float *_table;
-	int _bitPrecision;
 	double _radResolution; // Smallest radian increment
 	int _refSize; // _nPoints / 4
 	int _nPoints; // range of operator[]
diff --git a/common/sinetables.cpp b/common/sinetables.cpp
index c85a7bf..1dce529 100644
--- a/common/sinetables.cpp
+++ b/common/sinetables.cpp
@@ -27,12 +27,11 @@
 
 namespace Common {
 
-SineTable::SineTable(int bitPrecision) {
-	assert((bitPrecision >= 4) && (bitPrecision <= 16));
+SineTable::SineTable(int nPoints) {
+	assert((nPoints >= 16) && (nPoints <= 65536)); // log2 space is in [4,16]
+	assert(nPoints % 4 == 0);
 
-	_bitPrecision = bitPrecision;
-
-	_nPoints = 1 << _bitPrecision;
+	_nPoints = nPoints;
 	_radResolution = 2.0 * M_PI / _nPoints;
 	_refSize = _nPoints / 4;
 	_table = new float[_nPoints / 2];
diff --git a/common/sinetables.h b/common/sinetables.h
index f91592c..5a5f246 100644
--- a/common/sinetables.h
+++ b/common/sinetables.h
@@ -28,40 +28,34 @@ namespace Common {
 class SineTable {
 public:
 	/**
-	 * Construct a sine table with the specified bit precision
+	 * Construct a sine table given the number of points
 	 *
-	 * @param bitPrecision Precision of the table, which must be in range [4, 16]
+	 * @param nPoints Number of distinct radian points, which must be in range [16,65536] and be divisible by 4
 	 */
-	SineTable(int bitPrecision);
+	SineTable(int nPoints);
 	~SineTable();
 
 	/**
 	 * Get pointer to table
 	 *
-	 * This table contains 2^bitPrecision/2 entries.
+	 * This table contains nPoints/2 entries.
 	 * Prefer to use at()
 	 * The layout of this table is as follows:
-	 * - Entries 0 up to (excluding) 2^bitPrecision/4:
+	 * - Entries 0 up to (excluding) nPoints/4:
 	 *           sin(0) till (excluding) sin(1/2*pi)
-	 * - Entries 2^bitPrecision/4 up to 2^bitPrecision/2:
+	 * - Entries 2_nPoints/4 up to nPoints/2:
 	 *           sin(pi) till (excluding) sin(3/2*pi)
 	 */
 	const float *getTable() { return _table; }
 
 	/**
-	 * Returns sin(2*pi * index / 2^bitPrecision )
-	 * Index must be in range [0,2^bitPrecision-1]
+	 * Returns sin(2*pi * index / nPoints )
+	 * Index must be in range [0, nPoints - 1]
 	 */
 	float at(int index) const;
 
-	/**
-	 * Get bit precision
-	 */
-	int getBitPrecision() { return _bitPrecision; }
-
 private:
 	float *_table;
-	int _bitPrecision;
 	double _radResolution; // Smallest radian increment
 	int _refSize; // _nPoints / 4
 	int _nPoints; // range of operator[]


Commit: e859a6f13e97a72407d031c60554550d5adb64d7
    https://github.com/scummvm/scummvm/commit/e859a6f13e97a72407d031c60554550d5adb64d7
Author: David Fioramonti (dafioram at gmail.com)
Date: 2018-08-18T16:30:57+02:00

Commit Message:
BLADERUNNER: Update cos/sin table constructor change

They now take in the size rather than the power of 2 exponent.

Changed paths:
    engines/bladerunner/bladerunner.cpp


diff --git a/engines/bladerunner/bladerunner.cpp b/engines/bladerunner/bladerunner.cpp
index 4ad3ab0..362e0c4 100644
--- a/engines/bladerunner/bladerunner.cpp
+++ b/engines/bladerunner/bladerunner.cpp
@@ -315,8 +315,8 @@ bool BladeRunnerEngine::startup(bool hasSavegames) {
 	// Seed rand
 
 	// TODO: Sine and cosine lookup tables for intervals of 1.0, 4.0, and 12.0
-	_cosTable1024 = new Common::CosineTable(10); // 10-bits = 1024 points for 2*PI;	
-	_sinTable1024 = new Common::SineTable(10);	
+	_cosTable1024 = new Common::CosineTable(1024); // 10-bits = 1024 points for 2*PI;	
+	_sinTable1024 = new Common::SineTable(1024);	
 
 	_view = new View();
 


Commit: da57cef0c34162789100ea25eb0f4f3f7a1e90bf
    https://github.com/scummvm/scummvm/commit/da57cef0c34162789100ea25eb0f4f3f7a1e90bf
Author: David Fioramonti (dafioram at gmail.com)
Date: 2018-08-18T16:30:57+02:00

Commit Message:
COMMON: FFT update cos/sin table constructor change

They now take in the size rather than the power of 2 exponent.

Changed paths:
    common/fft.cpp


diff --git a/common/fft.cpp b/common/fft.cpp
index a750792..30e5449 100644
--- a/common/fft.cpp
+++ b/common/fft.cpp
@@ -37,6 +37,7 @@ FFT::FFT(int bits, int inverse) : _bits(bits), _inverse(inverse) {
 	assert((_bits >= 2) && (_bits <= 16));
 
 	int n = 1 << bits;
+	int nPoints;
 
 	_tmpBuf = new Complex[n];
 	_expTab = new Complex[n / 2];
@@ -48,8 +49,10 @@ FFT::FFT(int bits, int inverse) : _bits(bits), _inverse(inverse) {
 		_revTab[-splitRadixPermutation(i, n, _inverse) & (n - 1)] = i;
 
 	for (int i = 0; i < ARRAYSIZE(_cosTables); i++) {
-		if (i+4 <= _bits)
-			_cosTables[i] = new Common::CosineTable(i+4);
+		if (i + 4 <= _bits) {
+			nPoints = 1 << (i + 4);
+			_cosTables[i] = new Common::CosineTable(nPoints);
+		}
 		else
 			_cosTables[i] = nullptr;
 	}


Commit: 0805ac2be355659229f960f6fa3a889afa2d2ddc
    https://github.com/scummvm/scummvm/commit/0805ac2be355659229f960f6fa3a889afa2d2ddc
Author: David Fioramonti (dafioram at gmail.com)
Date: 2018-08-18T16:30:57+02:00

Commit Message:
STARTREK: Update cos/sin table constructor change

They now take in the size rather than the power of 2 exponent.

Changed paths:
    engines/startrek/startrek.cpp


diff --git a/engines/startrek/startrek.cpp b/engines/startrek/startrek.cpp
index e0aef01..cbbadc2 100644
--- a/engines/startrek/startrek.cpp
+++ b/engines/startrek/startrek.cpp
@@ -53,7 +53,7 @@ StarTrekEngine::StarTrekEngine(OSystem *syst, const StarTrekGameDescription *gam
 	_spockActor(&_actorList[1]),
 	_mccoyActor(&_actorList[2]),
 	_redshirtActor(&_actorList[3]),
-	_sineTable(10) {
+	_sineTable(1024) {
 
 	if (getPlatform() != Common::kPlatformDOS)
 		error("Only DOS versions of Star Trek: 25th Anniversary are currently supported");


Commit: 47c0e2701796962edd946ae463ae92ba806c4280
    https://github.com/scummvm/scummvm/commit/47c0e2701796962edd946ae463ae92ba806c4280
Author: David Fioramonti (dafioram at gmail.com)
Date: 2018-08-18T16:30:57+02:00

Commit Message:
STARTREK: Simplify sine table usage

The if checks that StarTrekEngine::sin is doing to evaluate the
correct index for the sine table lookup are already done in
Common::SineTable::at().

Changed paths:
    engines/startrek/math.cpp


diff --git a/engines/startrek/math.cpp b/engines/startrek/math.cpp
index 114ec5c..7770ed3 100644
--- a/engines/startrek/math.cpp
+++ b/engines/startrek/math.cpp
@@ -37,15 +37,7 @@ Fixed14 StarTrekEngine::sin(Angle angle) {
 	else if (i == 0x300)
 		return -1.0;
 
-	float f = 0.0;
-	if (i < 0x100)
-		f = _sineTable.getTable()[i & 0xff];
-	else if (i < 0x200)
-		f = _sineTable.getTable()[256 - (i & 0xff)];
-	else if (i < 0x300)
-		f = -_sineTable.getTable()[i & 0xff];
-	else if (i < 0x400)
-		f = -_sineTable.getTable()[256 - (i & 0xff)];
+	float f = _sineTable.at(i);
 	return Fixed14(f);
 }

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